Sonic 3 + Sonic & Knuckles "Boss Guide"

 Dueling in the Death Egg...(Sonic & Tails only)

ACT 1 BOSSES:
(Technically, it's the same boss in 2 different forms ;)
When you first reach it, 8 balls rotate around it.  Each hit on the red eye in the center causes one of those balls to explode (and send out damaging shards!).
Generally, you'll be safe in the far corners while the balls are spinning madly at ground level.

Round 2--fight!
The part with the eye comes out of the central cylinder and tries to home in on you while 2 spiked platforms spin around it.  Try to get on one of those platforms and launch your attacks from there.  Stay in the middle of the platform, cuz as soon as you hit the eye, those platforms will rotate -very- quickly and there's a good chance you'll get tossed off if you're on the edge.
It also fires a huge blast down from the bottom (below the eye part).  As usual, 8 hits will bring this machine down.

ACT 2 BOSSES:
Round 1: Gravity can be your friend (or foe) while trying to take out this land-mine dropping orb.  Don't try attacking the orb directly--you'll just bounce off of its shield.   There are 4 transporter chambers (one in each corner of this 2-screen-wide area).  Using one will cause gravity to reverse direction, thus dropping any landmines--hopefully on top of the orb.

Round 2: You chase Robotnik, only to see him jump into a red 'bot so huge, you can't see it on the screen all at once!  The big guy tries to smash you with his 6 fingers, which are only safe to hit -after- they've struck.

Round 3: With the fingers destroyed, Robotnik turns to another feature on his giant robot--namely a HUGE cannon that's powered by the Master Emerald he stole from the Floating Island.

Round 4: Robotnik tries to escape with the Master Emerald.  Keep running to the right or you'll fall off the crumbling platform!